Positive effect of resection quality on recurrence-free and overall survival in patients with glioblastoma has been shown in several studies. Fluorescence navigation is one of the methods increasing extent of resection. However, possible causes of incomplete resection may be misinterpretation of fading fluorescence or missed fluorescent tumor tissue due to lack of direct visibility between tumor tissue and microscope.

OBJECTIVE

To evaluate the effect of fluorescence navigation and endoscopic assistance on resection quality and outcomes; to analyze whether endoscope in fluorescence mode can overcome some limitations of resection following surgery under fluorescence-guided microscope.

MATERIAL AND METHODS

The study included 10 patients who underwent glioblastoma resection under fluorescence microscopic and endoscopic control. In 5 patients, 5 ALA (Alasens) at a dose of 20 mg/kg was used as a fluorescence inducer, in 5 patients — chlorin e6 (Photoditazine) at a dose of 1 mg/kg. Initially, microsurgical resection of all fluorescent tissue was performed using a microscope. Then, resection cavity was scanned with endoscope. Fluorescent tissue not visualized by microscope was additionally removed with subsequent morphological analysis.

RESULTS

Endoscope fluorescence detection thresholds were lower than microscope thresholds at working distances of 30 and 10 mm. In all patients, additional fluorescent tissue was detected after endoscopy. This tissue was completely resected in all cases. Histological examination confirmed tumor tissue in additionally resected areas. Total resection was achieved in all cases as evidenced by postoperative contrast-enhanced MRI.

CONCLUSION

Endoscopic resection of glioblastomas with fluorescence navigation significantly increases the rate of total resection. It is a useful adjunct to microscopic resection under fluorescence control.